In a perfect environment steel corrodes very slowly and offers strength
and durability for a variety of structural applications. The environment
most masonry reinforcing is exposed to, however, is usually less than
perfect, and the premature corrosion of steel reinforcement may ultimately
lead to failure of the structure.
The corrosion products which form on steel have much greater volume than
metal from which they form. This increase in volume produces a build up of
internal "bursting" pressure between the reinforcement and the
surrounding mortar or concrete. When the pressure increases beyond the
tensile strength of the masonry, the walls crack. As corrosion proceeds,
longitudinal and transverse cracks widen, and may cause spalling of the
joints. The presence of hairline cracks may not indicate evidence of
impending structural distress. However, their presence may be considered a
"failure" by the general public, and costly maintenance may be
necessary to keep up public confidence in the structure and to prevent
further corrosion.
Carefully controlled tests, and decades of experience in the field, have
shown that hot dip galvanizing of the steel reinforcement will materially
increase the life of reinforced structures. Hot dip galvanizing is the
process of coating a prepared steel surface by immersion of the work in
molten zinc. The hot dip galvanized coating consists of a series of
distinct zinc-iron alloy layers. The coating is unique in that it is
metallurgically bonded to the steel substrate. The strength of the bond is
measured in the range of several thousand psi, which insures that the
coating will not be damaged during normal handling. The zinc-iron alloys
of a galvanized coating have hardness values which equal or exceed those
of most structural steels, offering excellent abrasion resistance for
applications such as masonry wire reinforcing. The pure zinc layer and the
zinc-iron layers are anodic to steel, providing sacrificial or "cathodic"
protection in the event the coating is scratched or damaged.
Zinc metal has a number of characteristics that make it well suited for
use as a coating for protecting steel wire products. Its excellent
corrosion resistance and its ability to form dense, adherent, corrosion
product films, and a rate of corrosion some 10 to 100 times below that of
ferrous materials, depending upon the atmosphere, accounts for its
successful use as a protective coating in a variety of products and
exposure conditions.
All hot dipped WIRE-BOND® products are galvanized in accordance with ASTM
A153 Standards to insure the longest life possible for our products. The
marginal increase in cost for galvanizing is more than offset by the extra
service life added to our product by the galvanizing process.
WIRE-BOND®
Corporate Office
400 Roundtree Rd
P.O. Box 240988
Charlotte, NC 28224
Tel: (704) 525-5554
Toll-Free: (800) 849-MRCA (6722)
Fax: (704) 525-3761
Web site: http://www.wirebond.com
Memphis Plant
2365 Harbor Ave.
Memphis, TN 38113
Tel: (901) 775-9444
Toll-Free: (800) 441-8359
Fax: (901) 775-9449
04082/MAS
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